docs: def _compute_f2_factor(self, rrup):
          """
          Compute and return factor f2, see equation (5), 5th term, pag 2191
          """
          # f2 = max(log10(rrup/R2),0)
          f2 = np.log10(rrup / self.COEFFS_IMT_INDEPENDENT['R2'])
          f2[f2 < 0] = 0.0
  
          return f2